nAst1: Progress and Concepts Thread

[Superdave]

I do... but i don't have an IAC motor so it wouldn't help.

With a big cam it might help to build a little more vacuum, probably not enough to really make a difference though.

[robertisaar]

i have two reasons that i've used to consider it:

1. weak battery/alt in the wife's GP, it likes to blink the headlights pretty severely every time the brakes light up and it tends to effect idle speed a bit too much for my liking.

2. brake triggered accessories... i happen to be a big fan of the drum rears used on most of the 95-99 Monte Carlos, but like any drum setup, they have heat build-up issues whenever they get used hard, so i was thinking that whenever the brakes are applied, i could trigger a fan to come on to assist in cooling. not quite sure how to integrate all of the hardware for this, but it's a thought at least.

[robertisaar]

somewhat of an update, and another thought....

tried the single-fire code with the max allowable BPW set a little lower this time, got to a maximum of ~92.5% DC in single-fire, so it's certainly in range of a 3.1 w/16.7 lb/hr injectors now...

and then this thought occurs: when in single-fire, the way the ECM deals with it is by doubling the BPW on one cycle, and cutting fuel completely on the other. it does this by writing a BPW of 0.00mSec on the injector register, and for the fueling cycle it writes whatever mSec is calculated to the injector register. now, when in single fire, if there is an injector pulse already in progress, and 0.00 is written to the register it will instantly stop flowing fuel, regardless of how long the injectors should have been open, which is why in single-fire, we're limited to 50% of the 4 stroke cycle to inject the fuel necessary. now, what happens if i bypass the part of the code that would write the 0.00mSec BPW for the fuel off cycle? should allow single fire at times without worrying about running into that cutoff, huh?

i think i'll go try this before posting it though.

[robertisaar]

http://www.cars.com/go/search/detail/photos/multiPhotoPopup.jsp?paId=396485668&tracktype=usedcc&aff=national#0

anyone else like this concept?

[tkoforpresident]

hell yeah, that's *kind* of like how my old 94 saturn had a "performance" switch that would slightly increase shifting firmness. It was kind of a joke really... I think that motor had 80hp.

But no doubt, you're talking about a serious increase in power over stock from one to the other.

I think that would be sweet.

[robertisaar]

well, the idea here is to tune whatever vehicle in the full power mode, then either have a hidden toggle/key switch or a clearly visible switch(whichever you might like), then when above a certain amount of throttle(say 30%), spark is reduced to cut some power. at ~30%, you should be well within the range you would need for normal driving so you won't take any kind of fuel economy hit, but should you have someone driving it that you don't necessarily want having full power, it will tone it down should they decide to go full banana. i'm not sure if i want to make it just a static retard, or one based on engine speed to make it less noticable. possibly a lower speed/rev limiter as well....

[95cutlassproject]

I would love to have something like that. Though now you do have me thinking if i should hide or make it visable.

[robertisaar]

it would be possible to daisy-chain both a hidden AND visible one.....

[robertisaar]

update:

long time coming, nAst1 1.03 is delivered. changelog:

the possibility of factory alpha-n is completely removed from both the XDF and the BINs. if you want alpha-n style fueling or spark, check the bottom of the list of scalars, you'll find the option for either.

single-fire fueling is now the default firing method until the double-fire BPW would reach ~6.5mSec, then double-fire is enabled until double-fire BPW drops under 6mSec, then single-fire is enabled. with these settings on a 3.1 w/16.7 lb/hr injectors, i got into the high 80% duty cycles at the very highest before popping into double-fire. other combos may need tweaking, and there is a portion of the ADX dedicated to this.

the fueling histograms are now BLM based only, since when combining BLM and INT, it seemed to result in inconsistent fueling changes from log to log.

"autotuner" included in the ZIP, basically, copy/paste is all that's ever done when moving data in or out of the spreadsheet, the only exception being if you don't have enough samples in a cell that you want to make fueling changes for, then just change the BLM cell to 1.000. you'll notice the autotuner only does the low and mid RPM tables... i really don't think anyone should be relying on closed loop narrowband fueling at any time above 5200 RPM, hence the lack of a table.



for the time being, i'm halting the quest for fulltime single-fire fueling, though when i have my testbench up, it will resume.... it seems i still have some more to learn about how PCMs actually work.

when i am finished with the 1.xx series of BINs(which will be either when i run out of PROM space for a 32K BIN or when the added SRAM of a 9396/similar PCM is absolutely needed), i'm planning on releasing my full set of notes, the added source code and my most current hack of normal A1 operations, just in case anybody should want to use nAst1 as a stepping stone into their own custom mask.



EDIT: as a quick(LOLOL) project, are there any non A1 calibrations that anyone would like to see ported to the nAst1 code? i'm thinking of the latest 91-93 3.4 calibrations would be a good bet....

i guess some of the earlier A1 files(meaning not one of the 4 i update) might be wanted as well....

EDIT 2: already outdated! check down a few posts!

[pocket-rocket]

EDIT: as a quick(LOLOL) project, are there any non A1 calibrations that anyone would like to see ported to the nAst1 code? i'm thinking of the latest 91-93 3.4 calibrations would be a good bet....

Now why would you say that? Mines not stock though. My engine isn't 100% stock either. The base would be nice though as I have some plans for changes this summer. I'm probably going to hate driving the car without the nice monster front brakes on squishy 16" tires, but it's way better than letting it sit there and rot because I don't have $1200 for rims and $800 for tires.

[robertisaar]

BTW, it's seems i'm SLIGHTLY insane!!!

new package, now every A1 BIN i have ever found is either natively running on nAst1 1.03 or i ported them. not sure how many people would benefit from it, but here they are.

[robertisaar]

Now why would you say that? Mines not stock though. My engine isn't 100% stock either. The base would be nice though as I have some plans for changes this summer. I'm probably going to hate driving the car without the nice monster front brakes on squishy 16" tires, but it's way better than letting it sit there and rot because I don't have $1200 for rims and $800 for tires.

well, if you have your $DF tune and a decent XDF handy, compare the DF tune to the basis tune using one instance of tunerpro, then open another instance with the yet-to-be-released $A1 3.4 BIN and then copy the differences you see into the A1 tune, then you have your DF tune in A1 format.

[pocket-rocket]

I will do that, but right now the knuckles still need swapped and a new Optima purchased to get it going where I will drive it again and I'm a bit short on time/energy/motivation in the next couple weeks so it has to wait I will do this when I'm ready to drive it though.

[robertisaar]

some interim release info: it seems that in stock A1 form, when in BLM cell 2, the BLM does not get updated... i have this issue fixed for the next release.

next, in preperation for wideband usage, i need to figure out why during PE events, the stoich AFR will sometimes pop up and go away randomly, even though watching the BPW and O2 readings indicate that it is not used for fueling calcs.... when that's fixed, expect nAst1 1.031

should only be a few days at most, though a good run on a testbench(i swear, i'm in the process of planning/building my own) would be able to confirm the changes faster since it doesn't always occur, but when i'm confident i have it fixed, i think i'll.... clean the carbon out of the GP.

[Superdave]

Robert, have you found anything to the order of an Optical VSS flag in $A1? I searched and didn't find it but you never know.

The Fbody (89 and older) use an optical vss @ 2000ppm. The '7730 is set up to take this signal at C6 but there needs to be a flag changed (on the V8 bins).


Thanks